Driving Node
A Driving Node is the node that gets the command to run() each test. It is notified by the computer to begin testing.
The Driving Node is always ID 0, and is the only node that executes SetUp.run(), TestCase.run(), and TearDown.run().
The Driving Node is always the first node defined in a Test Run in the tunit.xml file. Any other node taking place in a test run is known as a Supporting Node.